Oscillometry, also known as Forced Oscillation Technique (FOT), is a noninvasive method to measure how easy is it is for the air to move in and out the respiratory system. Such “impediment” is quantified by combining the force used to move the air (i.e. the pressure stimulus provided by the device) with the amount of air that actually has been displaced (i.e. air flow) and calculating the RESPIRATORY IMPEDANCE.
Mathematically it is possible to separate such contributions by splitting IMPEDANCE into RESPIRATORY RESISTANCE (Rrs) and REACTANCE (Xrs).